Parasitology Overview Flashcards
Mutualism
beneficial for both
Commensalism
beneficial for one and only neutral to the other
Parasitism
beneficial for one but harmful to the other. Parasite vs Host
What is a Parasite
Organism that feeds and grows in or on a host with detriment to the host
A. Ectoparasite, infestation on or within the skin
Arthropods
B. Endoparasite, infection from inside the body
Protozoans and helminths
What is is defininitive host
Harbors the sexual stage of parasite’s life cycle
Like Schistosoma needs humans
Intermediate Host
Supports asexual reproduction or development of a parasite
Like Plasmodium in some parts of its cycle in humans
Incidental host
Accidental or dead end
Represents non-obligatory part of parasite’s life cycle
Toxoplasma
Resevoir host
is an animal species that maintains the parasite’s life cycle in the wild, e.g. mice for toxoplasma
Vector
Is a host species that transmits infectious form of parasite to another host, e.g. mosquitos - plasmodium
CDC’s Top 5 neglected parasite infections in the US
Chagas Disease by Trypanosoma Cruzi
Cysticercosis caused by Taenia Solium
Toxocariasis by Toxocara Canis or Cati
Toxoplasmosis by Toxoplamsa Gondii
Trichomoniasis by Trichomonas Vaginalis
Immune response to parasites
No consistent host immune response to parasites
- Worm infections typically involve eosinophils and Th2 response
- Most protozoan parasites elicit a Th1 response
Egg
Product of sexual reproduction that contains embryonated pre-larval form
Larva
Immature post-ovum (pre-adult) form
Cyst
Dormant stage encapsulated in host tissues
Cysticerci
Encysted cestode larvae in tissues of intermediate host, e.g. pork tapeworm in humans
